1. Field of the Invention
The invention relates to a sampling and infusion connector for an extracorporeal blood circulation line.
2. Description of the Related Art
As is known, lines for circulating blood outside the body, such as those used in a dialysis apparatus, need at least one connector for attachment to a blood line, the connector having a port for sampling blood and/or for infusing liquids into the blood flow. The flow is controlled by a pump, preferably peristaltic, which acts via rollers or the like on a flexible duct portion of the line.
A known connector for an aforementioned line comprises a tubular body having a blood inlet, an infusion opening, and a sampling opening located between the blood inlet and the infusion opening, the sampling opening for permitting test quantities of blood to be withdrawn such as through a syringe. This related art arrangement has the disadvantage that, during sampling, the infusion liquid tends to be sucked back in counter-current by the negative pressure caused by the sampling syringe, thereby mixing with the sampled blood and altering its composition.
Thus, in the related art, in order to prevent the infusion liquid from reaching the sampling aperture at the moment when suction is exerted by the syringe, it is necessary to interrupt the infusion process for a period of time, which can cause adverse effects on the treatment. Alternatively, the connector could be constructed so that the sampling aperture is disposed at an appreciable distance from the infusion aperture, in which case the connector would be bulky and inconvenient to use.